A semiconductor light emitting device using a nitride-based III to V group compound semiconductor such as gallium nitride (GaN) is applied to a high-luminance light emitting diode (LED) of ultraviolet to blue/green or a laser diode (LD) of blue-purple to blue, for example.
In a semiconductor light emitting device, an injection current is increased in order to obtain light emission of a high output. On this occasion, when the distribution of injection current is uneven in the device, at a part where an injection current density is excessively large, quantum efficiency lowers and light emission efficiency also lowers. Further, reliability may deteriorate sometimes due to heat generation.
Patent Literature 1 discloses, in a semiconductor light emitting device of a surface mounting type using an optically transparent positive electrode, a structure that allows a pad electrode to reduce photo absorption by providing a structure having two regions including a region of a high sheet resistance and a region of a low sheet resistance in the positive electrode. Even with such a structure, however, there still is a room for improvement in increasing efficiency.